Apparatus and method for making bulky yarn

ABSTRACT

AN APPARATUS FOR MAKING A BULKY TEXTILE YARN HAVING AT LEAST TWO GROUPS OF FILAMENTS COMBINED TOGETHER WITH EACH GROUP ALTERNATELY FORMING CORE AND EFFECT FILAMENTS IN THE COMPOSITE YARN. THE APPARATUS INCLUDES MEANS FOR ALTERNATING THE FEED SPEED OF THE FILAMENT GROUPS PASSING TO A FLUID BUCKLING APPARATUS WHICH COMBINES THE GROUPS IN A PATTERN DEPENDENT UPON THE FEED SPEED RELATIONSHIP, AND A MEANS FOR SETTING THE FILAMENT PATTERN SO THAT THE COMPOSITE YARN RETAINS THE FILAMENT PATTERN.

Sept. 20, 1971 c. F. SCHROEDER APPARATUS AND METHOD FOR MAKING BULKY YARN Original Filed Jan. 5. 1967 2 Sheets-Shut 1 J 50 LZ M wm WWO W 4/ INVINTHR' EHAHLEE' 1 SCHHUEDEH IIE' M "M .ATTYS.

P 20, 1971 c. F. SCHROEDER 3,605,393

APPARATUS AND METHOD FOR MAKING BULKY YARN Original Filed Jan. 3, 1967 2 Sheets$heat a II E B I mvuwnm;

CHARLES F 555120217511.

ATT'YB.

United States Patent 3,605,393 APPARATUS AND METHOD FOR MAKING BULKY YARN Charles F. Schroeder, Toledo, Ohio, assignor to Owens-Corning Fiberglas Corporation Original application Jan. 3, 1967, Ser. No. 606,894, now Patent No. 3,496,714, dated Feb. 24, 1970. Divided and this application June 11, 1969, Ser. No. 832,398 Int. Cl. D02g 1/20 US. Cl. 57-34 7 Claims ABSTRACT OF THE DISCLOSURE This is a divisional application of my co-pending application, Ser. No. 606,894, filed Jan. 3, 1967 now US. Pat. 3,496,714 granted Feb. 24, 1970.

This invention relates to a method of preparing a novel bulky textile yarn which, because of the arrangement of its constituent filaments, has improved and unique characteristics. More specifically, this invention relates to the method of combining a plurality of groups of filaments from separate sources, and, by programmed varia- Y tions in the feed speed of each of the groups to the point of combining, forming each of the groups of yarn alternately into core and effect (interior and surface) filaments of the composite yarn. Such yarn, when the undulation or waves are permanently heat set or otherwise fixed, has an elastic quality while retaining a high tensile strength and high resistance to separation.

The yarn prepared in accordance with this invention is especially desirable when comprised of groups of glass fiber filaments combined by a fluid texturing device. Because of the high tensile strength of glass fibers, the composite yarn is extremely strong in relation to its weight and, because of the unique arrangement of the groups of filaments in the composite yarn, such a glass yarn, is elastic when the convolutions or waves formed in the filaments are stress-relieved or heat set in accordance with this invention. It is to be understood that the yarn made by this invention may be also comprised from other natural and synthetic fibers or combinations of both and that it can be made from twisted or untwisted strands or even staple fibers or groups of filaments of random length. Thus, the term yarn as used herein is intended to include all such products.

A process for fluid texturing groups of filaments to form a bulky. or soft yarn is disclosed in US. Pat. 2,852,906. As disclosed in this patent, 'a yarn or strand of generally straight filaments is rapidly drawn through a fluid texturing jet wherein the filaments are subjected to high fluid turbulence. The filaments leaving the jet are 3,605,393 Patented Sept. 20, 1971 ice convoluted so that the end product has a distinctly different characteristic from the yarn or strand fed to the jet. An important part of this process is the necessity of overfeeding the yarn or strand to the jet so that the bulked yarn, when withdrawn, is not returned to its original condition.

US. Pat. 2,869,967 discloses a fluid texturing process and apparatus in which a plurality'of yarn or strand sources is fed to a single jet and are combined by the turbulent action of the jet into a single composite yarn. By overfeeding one of the yarn or strand sources at a larger rate in relation to the other, one of the yarn or strand sources becomes the core yarn and the other becomes the effect yarn. The core yarn generally remains substantially straight within the center of the composite bulked yarn, while the efiect yarns, because of their greater amount of overfeed, assume larger convolutions, waves and loops and are held in place by mechanical interlocking with the core yarns which remain relatively closely spaced to one another.

It is well known that glass fiber yarns and other synthetic yarns may be permanently crimped or fixed by means of heat setting. Other yarns may be permanently fixed or set by the application of an appropriate size, binder, solvent, softening agent or other medium. Heat setting or otherwise fixing the undulations is desirable when producing a yarn which is intended to be elastic, e.g., when tension is placed on the yarn the fixed undulations, convolutions, or crimps will straighten out and, when tension is released, they will resume their undulated or crimped form. Previous attempts to manufacture a satisfactory elastic yarn by overfeeding a single yarn or strand source to a fluid jet and heat setting or otherwise fixing the convolutions in the yarn exiting from the jet have been made. While such yarns do in fact have some elasticity, they do not provide the desired properties for many uses due to the fact that because all of the filaments are highly convoluted or waved, their mechanical interlinkage is not such as will provide uniformly distributed or controlled limited extensibility when tension stress are applied.

It has been discovered that a highly satistfactory elastic yarn may be made of glass fibers or other materials using at least two separate yarn sources which are supplied to a combining means, such as a fluid jet, and each of the yarn sources, due to predetermined variations in the amount of overfeed to the jet, become, in essence, both core and effect yarns in alternate spaced portions along the composite yarn. By alternately feeding one of the yarn sources faster than the other, this one yarn source will become a core yarn for a given distance in the composite yarn, through which distance the other yarn source becomes the effect yarn. By rapidly alternating the variations in speed, short sections of the composite yarn are formed in which the core and effect yarns interchange from one source to another. The composite yarn so formed has the desirable property of retaining the ability to be stretched by mechanical disengagement of the interlinked mechanical deformations, or elastically stretched, when the deformations are heat set or otherwise fixed. Because of the presence of core yarns in each of the sections for closely binding the various deformations of the effect yarns together, the problem of separation of the filaments heretofore encountered has been eliminated.

Accordingly, it is an object of this invention to provide a method and apparatus for making novel yarn having elastic characteristics which retains superior properties of tensile strength and resistance to separating when subjected to forces normal to the axis of the yarn.

It is another object of this invention to provide a novel lofted yarn of glass fibers which, when stress-relieved or heat set, has the property of elasticity and also retains its high tensile strength.

It is another object of this invention to provide a method and apparatus for making novel yarn formed of at least two separate groups of filaments with each group of filaments alternately forming the effector surface filaments, and then the core or generally straight filaments within the composite yarn.

'Other objects and advantages of this invention will be apparent to those skilled in the art, reference being made to the accompanying drawings in which:

FIG. 1 is a schematic view of an apparatus for produc- V such as this may be used tandem to form the novel yarn ing the novel yarns of this invention, showing a mechanism for feeding a pair of separate filament groups to a fluid texturing jet, for taking up and winding the composite yarn formed therein and also showing a mechanism for heat setting the yarn as it leaves the texturing jet;

FIG. 2 is a schematic view showing another apparatus which may be used to form the novel yarn of this invention;

FIG. 3 is a schematic view on an enlarged scale of a section of the novel yarn of this invention which would be formed by the apparatus of FIG. 2, showing, for the purpose of clarity of illustration, the path of a single filament from each of the separate yarn sources;

FIG. 4 is a schematic view on an enlarged scale, of a novel yarn of this invention which would be formed from the apparatus of FIG. 1, showing, for the purpose of clarity of illustration, the path of a single filament from each of the separate yarn sources;

FIG. '5 is a schematic view of another apparatus for .producing a novel yarn of this invention, showing another mechanism which includes pairs of driven gears which engage separate yarn sources in an out-of-phase relationship and feed such sources to a combining device such as a fluid jet; I

FIG. 6 is a schematic view on an enlarged scale of a novel yarn of this invention which would be formed on the apparatus of FIG. 5, showing, for the purpose of clarity of illustration, the path of a single filament from each of the yarn sources;

FIG. 7 is a schematic view of another apparatus for producing a novel yarn of this invention having three separate yarn sources fed by three pairs of driven gears .to a combining device; and

FIG. 8 is a schematic view on an enlarged scale of a novel yarn of this invention which would be produced on .the apparatus of FIG. 7, showing, for the purpose of ,clarity of illustration, the path of a single filament from each of the yarn sources.

' Preparation of a novel yarn previously described is, in

general, accomplished by feeding at least two separate sources of yarn to a combining means, such as a fluid texturing jet, and, by means of apparatuses of the type shown "It is to be emphasized that the apparatuses illustrated in these figures are only examples of a number of types of mechanisms which may be used to accomplish the desired results. For instance, U.S. Pat. 2,948,931 discloses an apparatus for varying the feed rate of a single yarn source .with appropriate controls for setting the magnitude of the speed changes and the frequency thereof. Apparatuses of this invention.

Referring to FIG. 1, a fluid jet 10 such as of the type disclosed in U.S. Pat. 2,783,609 is provided having a yarn inlet nozzle, a yarn outlet orifice and an air supply means which is connected to a source of air pressure. The interior construction and operation of such jets is well known to those skilled in the art and will not be discussed in detail. A pair of yarn spindles or supplies 11 and 12 are positioned above the jet 10 and the yarn or strand therefrom is led through pigtails 13-16 and downwardly through yarn guides 17 and 18 which are spaced apart and secured to a reciprocating platen 19. Each of the groups of filaments, designated A and B, is then wound around the outer surface of a frusto-conical feed roller 20 and 21, respectively, and thence guided by a second pair of pigtails 22 and 23 to the inlet orifice of the jet 10'. As is well known to persons skilled in the art, it is desirable that the yarns enter the inlet orifice jet 10 at an angle from the axis of the jet, as shown in FIG. 1. The reciprocating platen 19 may also be driven by the motor M through an appropriate mechanism for converting rotary movement to reciprocating movement. The mechanism including the platen 19 must be capable of high speed reciprocation. U.S. Pat. 3,171,608 discloses one such suitable mechanism and others capable of such high speed movement are known to those skilled in the art.

Frusto-conical feed rollers 20 and 21 are spaced apart and secured to a common drive shaft 24 which is supported by bearings 25 and 26 and is directly driven by a motor M through a gear box 27. As shown in FIG. 1, the coaxial feed rollers 20 and 21 have their smaller or minor diameters adjacent each other. However, the larger or major diameters may be adjacent one another so that, in either case, the slopes of the rollers would intersect one another intermediate the rollers in an axial direction. A take-up roller 28 is secured to a shaft 29 supported by bearings 30 and 31. The shaft 29 and thus the takeup roller 28 are driven by a belt or chain 32- which extends around pulleys 33 and 34 secured to the drive shaft 24 and the shaft 29, respectively.

The composite bulked yarn leaving the jet 10 is passed through a heat setting device, generally designated by reference numeral 35, is passed around the take-up roller 28 and is then guided and gathered upon a yarn winder 36 by a traverse mechanism 37.

In operation, the reciprocating platen 19 and associated yarn guides 17 and 18 are caused to rapidly oscillate between the full line position and the dotted line position, indicated by reference numerals 17a, 18a and 19a, so that the yarns .or strands A and B are directed along the surfaces of the frusto-conical feed rollers 20 and 21, respectively, moving up and down the axis of these feed rollers 20 and 21. It will be apparent that a change in the axial position of the yarn upon the feed rollers 20 and 21 will change the rate at which the yarn is fed to the jet 10, due to the difference in diameter at the point at which the yarn is turned upon the feed rollers '20 and 2.1. Thus, in the position shown in solid line, yarn'B, which is wrapped on the feed roller 21 at .a

relatively large diameter is fed at a faster rate than yarn A which is wrapped upon the feed roller 20 at a relatively .small diameter. At the other extreme position, the dotted .FIG. 4, the composite yarn formed in'the fiuidjet 10 is schematically illustrated, with only a single filament from each of the yarn sources A and B illustrated for purposes of clarity. It is to be understood that the actual yarn produced would include a large number of filaments from each group which would be more closely intermingled with one another.

Because the take-up rate of the composite yarn from the fluid jet is determined by the take-up roller 28 which is driven at a fixed speed in relation to the speed of the feed rollers 20 and 21, the effective diameter of the take-up roller 28 may be selected so that the take-up speed of the composite yarn from the fluid jet .10 is always slower than the slowest feed speed of either of the yarn or strand sources A or B. Thus, at all times, there is a slight amount of over-feed of each of the yarn sources. If the effective diameter of the take-up roller 28 is the same as the smallest effective diameter of feed rollers 20 and 2-1, that is, the smallest diameter of the frustoconical surface upon which the yarns A and B are directed by the platen 19' and yarn guides 17 and 118, at an instantaneous time when the platen 19 is in its extreme left or right hand position, there will be no overfeed of one of the yarn sources A or B. As illustrated in FIG. 4, the single filament from yarn source A has its greatest amount of bulkiness formed by filament undulations or convolutions in the spaced apart areas designated by ref erence numeral 38 and its least amount of bulk contractions or convolutions in interjacent areas designated by reference numeral 39. On the other hand, the filaments from the yarn source B, because the relative speeds of yarns A and B are inversely alternated, has its portions of least filament deformation in the areas designated by reference numeral 40 with interjacent areas of increased filament deformation designated by reference numeral 41. The areas 40 of yarn B are opposite to the areas 38 of yarn A, etc. As previously explained, the yarn B in these areas 40 is overfed only a slight amount and thus the yarn B, in these areas, forms a core yarn which remains realtively straight and is used to interlock and bind the deformations of the other yarn A in areas 38 together. In an adjacent segment, the yarn A in area 39 forms the core yarn and is used to bind together the fiber deformations of area 41 in yarn B. As previously explained, it is important that the composite yarn in all areas have some core filaments which are relatively straight and compactly positioned together to form a core yarn which holds the wave-like or convoluted deformations of the opposite number in place.

As previously explained, in order to give the composite textured yarn a resiliency, the bulked fibers therein are preferably heat set or otherwise fixed so that they return to their bulked configurated form upon release of the force extending them. This may be done, in the case of glass fibers, by stress-relieving or heat setting with the device 35- which may be a dielectric furnace or other appropriate heating device. Because the mass of the fibers is small, such fibers may be heat set while passing through the heating device at a very high speed. Other means of heat setting such as with a mufile furnace or radiant gas burners may be used. In addition to heat setting, other means of setting the desired configuartions in the fibers may be used.

It has also been determined that the coaction between the filaments in groups A and B, when combined, may be utilized in forming two separate bulky yarns, the characteristics of which are different from a composite yarn of both groups or a single fluid textured yarn. Using a modification of the apparatus shown in FIG. 1, the two groups of filaments A and B may be separated from one another and separately gathered on separate packaging devices, preferably after they have been permanently crimped or heat set while still in their engaged form. The separated yarns retain the same configuration which they assumed in the composite yarn, which configuration was at least in part due to the action of one set of filaments against the other when being combined. It will be apparent that the final configuration of each groupywill be dependent upon feed speed, relative take-up speed, etc., and that separate products having different configurations and qualities can be produced simultaneously in this manner.

Referring to FIG. 2, a second apparatus for forming the novel yarn of this invention is schematically illustrated again with a pair of yarn supplies 11 and 12 from which separate yarn sources A and B are directed through pigtails 13-16. In this device, the feed mechanism to the fluid jet 10 includes two pairs of intermeshed feed rollers 42-45. Each of the rollers 42-45 has a portion of its outer surface in the form of a smooth cylindrical drive surface and an opposed portion with intermeshing convolutions or gear teeth. The effective pitch diameter of the convolutions or gear teeth is the same as the diameter of the smooth portion. As shown, the rollers 42-45 have one-half of their circumference as the smooth portion and the other half as the gear portion. Depending, however, upon the amount of overfeed and the relative lengths of the overfed portions of the yarn desired, this ratio of smooth portion to toothed portion may be varied.

Referring to the drive roller 43, it will be apparent that the periphery of this portion, or half the circumference of the roller 43, designated as distance X in FIG. 2, will be less than the total surface distance over and around the surface of the convolutions of the toothed portion, designated as distance X +d on roller 44. With the feed rollers 42-45 in driving relationship as schematically illustrated in FIG. 2, and with the toothed portions of the pair of rollers 42 and 43 out of phase with the toothed portion of the rollers 44 and 45, the yarn sources A and B, when contacted by the roller pairs 42-45 will be pulled at inversely varying velocities. If all the rollers are driven at constant r.p.m., for a given half revolution, the yarn source A which is being driven by the toothed portion of the rollers 42 and 43 will move at a faster rate than the yarn source B which is being driven by the smooth portion of the rollers 44 and 45. For this half revolution of each pair of rollers 42-45, yarn A will be fed to the fluid jet 10 a distance of X +d while yarn B will be fed a distance of X. The overfeed resulting from the increased distance around the toothed portion, d, is schematically indicated by the undulating portions designated by reference numeral 46 which, as shown in FIG. 2, are in staggered relationship between yarn groups A and B. Thus, the effect of the feed rolls 42-45 is to alternately and sequentially overfeed yarns A and B relative to one another to the fluid jet 10. Similar to the apparatus illustrated in FIG. 1, a take-up roller 28 removes the composite yarn from the fluid jet 10 at a fixed speed in relation to the feed speeds and the yarn is subsequently wound on a take-up device (not shown).

Referring to FIG. 3, a single filament from each of the yarn sources A and B is illustrated for clarity to indicate the form of the two yarn sources A and B as they would be in the composite yarn formed by the apparatus of FIG. 2. Contrary to the apparatus of FIG. 1, the speed 'change of the yarn sources A and B fed by the apparatus of FIG. 2 relative to one another is not gradual but is abrupt as the yarn driving surfaces of the feed rollers 42-45 change from the convoluted portion to the smooth portion. Thus, the yarn A, as shown in FIG. 3, is extended in relatively straight form in portions 47 and contracted or convoluted into highly textured form in alternate portions 48 while the yarn B is correspondingly but inversely extended or relatively straight in portions 49 while contracted or convoluted into highly textured forms in portions 50. Because the speed change is abrupt, the change between a successive portion, such as portions 47 and 48 on yarn A, is not gradual, as is the case with the yarn shown in FIG. 4. In each case, however, the yarns in the relatively straight or untextured portions provide core or base section for mechanical interlinkage and holding of the other contracted or convoluted yarn portion in interlocked relation, as previously explained.

A liquid binder applicator 51 is schematically shown in FIG. 2 downstream of the fluid jet 10 to apply appropriate bonding material to the composite yarn as it leaves the texturing jet 10. It is to be understood that the deformation in the fiber can be fixed either by heat setting or the application of bonding material or any other method of permanently affixing the contracted deformations or crimps in the yarn may be used with either the apparatus shown in FIG. 1 or FIG. 2 or the apparatuses of FIGS. 5 and 7, described below.

Another apparatus for producing a novel lofted yarn comprised of separate filament sources interengaged with one another is schematically shown in FIG. 5. A first pair of driven gears 52 and 53 engages a yarn group A supplied from the yarn supply 11 and a second pair of driven gears 54 and 55 engages a yarn group B supplied from yarn supply 12. Each of the pairs 52, 53 and 54, 55 are driven in the direction of the arrows in FIG. 5 by an appropriate drive mechanism (not shown). The gears 54 and 55 are positioned on their respective drive shafts so as to be out-of-phase by a predetermined amount from the gears 52 and 53 so that successive pairs of teeth release increments of strand B shortly after increments of strand A have been released from the pairs of gears 52 and 53. With the teeth of the gear pairs 52, 53 and 54, 55 out-of phase as described, successive waves or portions under released tension are alternately supplied to the fluid jet out-of-phase with the waves or portions under released tension in the other yarn source. The yarn sources with out-of-phase waves are combined with one another to form a product schematically shown in FIG. 6. In this product, yarn sources A or B do not comprise core and effect yarns but interchange from one portion of the composite yarn to another in the manner illustrated.

It will be apparent that the amount of loft or bulk of the final product may be varied by varying the phase relationship between the pairs of gears 52, 53 and 54, 55 and also by the depths of the teeth which determines the ultimate depth and slope of the waves or undulations formed.

FIG. 7 schematically illustrates an apparatus for forming a lofty bulked yarn product from three separate yarn groups, A, B and C. Yarn groups A and B are fed to a fluid jet 10 by pairs of driven gears 56, 57 and 58, 59, respectively. Like the apparatus of FIG. 5, the gears 58 and 59 are out-of-phase with gears 56 and 57 so that alternate portions of released tension or waves in the groups A and B are successively supplied to the jet. Yarn group C from a yarn supply 60 is engaged by a pair of driven gears 61 and 62 which may have a surface speed different from the other pairs of driven gears so that the ultimate configuration of the group C yarns in the composite yarn shown in FIG. 8 is different from that of g the group A and B yarns.

' tuses which may be used to feed two or more yarn sources at varying rates with alternating portions of reduced tension successively presented to the combined means to produce the novel lofted products of this invention.

Each of the apparatuses schematically shown in FIGS.

, 1, 2, 5 and 7, as well as others, are capable of sequentially and alternately varying the relative speed of a plurality of yarn sources to a texturing jet and may be used to produce the novel yarn of this invention. More than two yarn sources can be combined in the same manner, as described, with each yarn source being fed to the jet in varying relative velocity to the others in accordance with a predetermined program. As previously stated, it has been found that yarns produced as described have superior properties and that when the crimps have been permanently set, by stress-relieving by heat or other means, the yarns of material having limited stretchability such as glass yarn has an elastic quality and also retains its high tensile strength and resistance to separation.

The bulked product of this invention can be woven into a fabric and then heat set or otherwise fixed to produce a lofted product. Upon application of stress to such a fabric it can be drafted by reason of disengagement of the mechanical interlinkage of fibers. This treatment can be utilized to shape the fabric to desired three-dimension configurations or to selectively impart desired localized differences in texture to the fabric. Still further, the fabric can be drafted uniformly to impart a uniformly lofted character to the fabric of texture somewhat different than is provided by the bulked yarn in its originally interlocked condition.

The textured product of this invention can also be provided with a coating of elastomeric material, or can be made of coated yarns impregnated with elastomeric material such as rubber which will impart a different, or additional degree of stretchability to the interlocked yarn. Such a product when positively interlocked with relatively limited or no draftability will have a stretchability because of the coating or impregnant material which, because of its compressability and cushioning property, results in stretch under stress whether in yarn or fabric form. In such instances product can also be limited in stretch to the mechanical limit of stretch of the overall bulk product. Other uses for a yarn formed with the apparatus of this invention will be apparent to those skilled in the art.

Various other modifications of the above-described invention may be made by those skilled in the art without departing from the scope of the attached claims.

I claim:

1. An apparatus for producing a bulky yarn having relatively straight core yarns and undulated surface effect yarns, comprising, in combination, a fluid texturing jet for combining at least two groups of filaments into a single composite yarn, at least two yarn sources for supplying at least two groups of filaments to said fluid jet, means for withdrawing such composite yarn from said fluid jet and means for feeding each of said groups of filaments to said fluid jet, each feeding means having an associated irregular surface for engagement of its filament group to feed said group to said fluid jet at alternately high and low relative speeds and out-of-phase with one another whereby said groups of filaments are alternately driven at low and high relative speeds with respect to one another whereby said one group of filaments alternately comprises the core and effect yarns of said composite yarn.

2. The apparatus of claim 1 wherein said feeding means comprises a pair of rotating gears having mating convolutions on a portion of their periphery and a cylindrical surface on the remaining portion of their periphery whereby, when said gears are driven at a constant angular speed, a group of filaments driven by and between said gears will be alternately driven at one speed by surface contact with said cylindrical portion and at a second speed by surface contact between said mating convolutions.

3. The apparatus of claim 1 which further includes means for permanently fixing the convolutions in such composite yarn as it is taken from said fluid texturing jet.

4. The apparatus of claim 1 which further includes means for heat setting such composite yarn taken from said fluid texturing jet.

5. The apparatus of claim 1 wherein said means for withdrawing such composite yarn from said fluid jet is a take-up roller having a surface speed slower than the slowest speed at which either of such groups is supplied to said jet whereby each of said groups is overfed at varying rates to said jet.

6. A method of producing a bulky yarn comprised of at least two groups of filaments interengaged with one another comprising the steps of passing each of said groups of filaments to an engaging zone with successive portions of each of said groups being under released tension with such portions in one of said groups alternating with such portions in the other of said groups, combining said groups in said engaging zone into a bulky yarn and removing said bulky yarn from said engaging zone.

7. The method of claim 6 which includes the further step of permanently setting the filaments in said bulky yarn.

References Cited UNITED STATES PATENTS 3,099,064 7/1963 Haynes 28l.3 5 3,328,863 7/1967 Cobb et al. 28-1.4

3,340,585 9/1967 Buckley et al. 2872.14X

3,457,610 7/ 1969 Williams et al 281.4

3,479,810 11/1969 Eshuis 57157X 10 LOUIS K. RIMRODT, Primary Examiner US. Cl. X.R. 

